U.S. patent application number 16/332251 was filed with the patent office on 2019-11-28 for adapting between synchronous and asynchronous operations based on numerology.
The applicant listed for this patent is Telefonaktiebolaget LM Ericsson (publ). Invention is credited to Mattias BERGSTROM, Muhammad KAZMI, Iana SIOMINA.
Application Number | 20190364520 16/332251 |
Document ID | / |
Family ID | 60083374 |
Filed Date | 2019-11-28 |
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United States Patent
Application |
20190364520 |
Kind Code |
A1 |
KAZMI; Muhammad ; et
al. |
November 28, 2019 |
ADAPTING BETWEEN SYNCHRONOUS AND ASYNCHRONOUS OPERATIONS BASED ON
NUMEROLOGY
Abstract
A method, wireless device, and network node configured to
determine a synchronization status for the wireless device based on
a first numerology and a second numerology, In one embodiment, a
method performed by a wireless device for determining a
synchronization status for the wireless device based on a first
numerology and a second numerology is provided. The method includes
estimating a time difference between receipt of a first downlink
signal received from a first network node, and receipt of a second
downlink signal received from a second network node, obtaining a
first downlink threshold based on the first numerology and the
second numerology, and determining the synchronization status of
the wireless device based on a relationship between the estimated
time difference and the first downlink threshold.
Inventors: |
KAZMI; Muhammad;
(SUNDBYBERG, SE) ; BERGSTROM; Mattias;
(SOLLENTUNA, SE) ; SIOMINA; Iana; (TABY,
SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Telefonaktiebolaget LM Ericsson (publ) |
Stockholm |
|
SE |
|
|
Family ID: |
60083374 |
Appl. No.: |
16/332251 |
Filed: |
September 28, 2017 |
PCT Filed: |
September 28, 2017 |
PCT NO: |
PCT/IB2017/055974 |
371 Date: |
March 11, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62402369 |
Sep 30, 2016 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 56/002 20130101;
H04W 8/22 20130101; H04W 56/00 20130101 |
International
Class: |
H04W 56/00 20060101
H04W056/00; H04W 8/22 20060101 H04W008/22 |
Claims
1-13. (canceled)
14. A wireless device configured to determine a synchronization
status for the wireless device based on a first numerology and a
second numerology, the wireless device comprising: a communications
interface; and processing circuitry configured to: estimate a time
difference between receipt of a first downlink signal received from
a first network node, and receipt of a second downlink signal
received from a second network node, the first numerology being
used for operating the first downlink signal and the second
numerology being used for operating the second downlink signal;
obtain a downlink threshold based on the first numerology and the
second numerology; and determine the synchronization status of the
wireless device based on a comparison between the estimated time
difference and the downlink threshold.
15. The wireless device of claim 14, wherein the first numerology
is used for operating the first downlink signal and the second
numerology is used for operating the second downlink signal.
16. The wireless device of claim 14, wherein the first network node
and the second network node are a same node.
17. (canceled)
18. The wireless device of claim 14, wherein the communications
interface is configured to indicate to another node, information
about capability of the wireless device related to support of at
least one of synchronous and asynchronous multi-connectivity.
19. (canceled)
20. The wireless device of claim 14, wherein the one or more
processors is further configured to use the determined
synchronization status of the wireless device for at least one
operational task, wherein the at least one operational task
comprises at least one of demodulation of received signals,
transmission of signals, radio measurements, at least one of
selection and application of a power control scheme, transmission
of at least one of the estimated time difference and an uplink
transmit time difference to another wireless device, transmission
of at least one of the estimated time difference and the uplink
transmit time difference to another network node, and indicating
the synchronization status of the wireless device to at least one
of another network node or another wireless device.
21. (canceled)
22. The wireless device of claim 14, wherein the one or more
processors is further configured to estimate a transmit time
difference between a first uplink signal transmitted by the
wireless device in a first cell operated by the first network node
and a second uplink signal transmitted by the wireless device in a
second cell operated by the second network node.
23. The wireless device of claim 14, wherein the downlink threshold
is selected from a table of thresholds corresponding to different
subcarrier spacings.
24. The wireless device of claim 14, wherein the synchronization
status of the wireless device is synchronized when the estimated
time difference exceeds the downlink threshold and is asynchronous
otherwise.
25. The wireless device of claim 14, wherein a magnitude of the
downlink threshold decreases with an increase in subcarrier spacing
used in at least one of a first downlink cell and a second downlink
cell.
26. The wireless device of claim 14, wherein a magnitude of a
second downlink threshold decreases with an increase in subcarrier
spacing used in at least one of a first downlink cell and a second
downlink cell.
27-35. (canceled)
36. A network node configured to determine a synchronization status
for a wireless device based on a first numerology and a second
numerology, the network node comprising: a communications interface
configured to: obtain, from the wireless device, an estimated time
difference between receipt, by the wireless device of a first
downlink signal received from a first network node, and receipt, by
the wireless device of a second downlink signal received from a
second network node, the first numerology being used for operating
the first downlink signal and the second numerology being used for
operating the second downlink signal; obtain a downlink threshold
based on the first numerology and the second numerology; and
processing circuitry configured to: determine the synchronization
status of the wireless device based on a comparison between the
estimated time difference and the downlink threshold.
37. The network node of claim 36, wherein the first numerology is
used for operating the first downlink signal and the second
numerology is used for operating the second downlink signal.
38. The network node of claim 36, wherein the first network node
and the second network node are a same node.
39. (canceled)
40. The network node of claim 36, wherein the communications
interface is further configured to obtain information about
capability of the wireless device related to support of at least
one of synchronous and asynchronous multi-connectivity.
41. (canceled)
42. The network node of claim 36, wherein the processing circuitry
is further configured to use the determined synchronization status
of the wireless device for at least one operational task, wherein
the at least one operational task comprises at least one of
reception of signal from the wireless device, transmission of
signals to the wireless device, scheduling of at least one of
uplink and downlink signals, radio measurements, timing advance
estimation, adaptation of configuration of measurement gaps,
adaptation of the discontinuous reception, DRX, configuration used
for the wireless device, adaptation of measurement configuration
sent to the wireless device, configuration of a timing advance
group, at least one of selection and configuration of a power
control scheme, and transmission of at least one of the estimated
time difference and an uplink transmit time difference to another
network node.
43. (canceled)
44. The network node of claim 36, wherein the communications
interface is further configured to obtain a transmit time
difference, estimated by the wireless device, between a first
uplink signal transmitted by the wireless device in a first cell
and a second uplink signal transmitted by the wireless device in a
second cell.
45-50. (canceled)
51. A wireless device configured to determine a synchronization
status for the wireless device based on a first numerology and a
second numerology, the wireless device comprising: processing
circuitry configured to: estimate a time difference between
transmission of a first uplink signal transmitted by the wireless
device and transmission of a second uplink signal transmitted by
the wireless device, the first numerology being used for operating
the first uplink signal and the second numerology being used for
operating the second uplink signal; obtain an uplink threshold
based on the first numerology and the second numerology; and
determine the synchronization status of the wireless device based
on a comparison between the estimated time difference and the
uplink threshold.
52. The wireless device of claim 51, wherein the first numerology
is used for operating the first uplink signal and the second
numerology is used for operating the second uplink signal.
53. The wireless device of claim 51, wherein the first network node
and the second network node are a same node.
54-60. (canceled)
61. A network node configured to determine a synchronization status
for a wireless device based on a first numerology and a second
numerology, the network node comprising: processing circuitry
configured to: obtain, from the wireless device, an estimated time
difference between transmission of a first uplink signal and
transmission of a second uplink signal, the first numerology being
used for operating the first uplink signal and the second
numerology being used for operating the second uplink signal;
obtain an uplink threshold based on the first numerology and the
second numerology; and determine the synchronization status of the
wireless device based on a comparison between the estimated time
difference and the uplink threshold.
62. The network node of claim 61, wherein the first numerology is
used for operating the first uplink signal and the second
numerology is used for operating the second uplink signal.
63. The network node of claim 61, wherein the first network node
and the second network node are a same node.
64-69. (canceled)
70. A wireless device for determining a synchronization status for
the wireless device based on a first numerology and a second
numerology defined for data transmission, the wireless device
comprising: processing circuitry configured to: estimate a
transmission time difference between a first signal and a second
signal exchanged between the wireless device and a first network
node and a second network node, respectively, the first numerology
being used for operating the first signal and the second numerology
being used for operating the second signal; obtain a threshold
based on the first numerology and the second numerology; and
determine the synchronization status of the wireless device based
on a comparison between the estimated transmission time difference
and the threshold.
71. The wireless device of claim 70, wherein the first signal is a
first downlink signal from the first network node and the second
signal is a second downlink signal from the second network node and
wherein estimating the transmission time difference comprises
estimating a time difference between receipt of the first downlink
signal received from the first network node and receipt of the
second downlink signal received from the second network node, and
wherein obtaining the threshold comprises obtaining a downlink
threshold.
72. (canceled)
73. The wireless device of claim 70, wherein the first signal is a
first uplink signal and the second signal is a second uplink signal
and wherein estimating the transmission time difference comprises
estimating a time difference between transmitting the first uplink
signal to the first network node and transmitting the second uplink
signal to the second network node, and wherein obtaining the
threshold comprises obtaining an uplink threshold.
74-84. (canceled)
Description
FIELD
[0001] The present disclosure relates to wireless communications,
and in particular, to a method, wireless device and network node
for adaptation between synchronous and asynchronous operations in a
wireless network based on numerology.
BACKGROUND
[0002] New Radio (NR) Architecture
[0003] NR (also known as 5G or Next Generation) architecture is
being discussed in Third Generation Partnership Project (3GPP) and
the current concept is illustrated in FIG. 1, where eNB denotes a
Long Term Evolution (LTE) eNodeB 1, gNB denotes a NR base station
(BS) 2 (one NR BS may correspond to one or more
transmission/reception points), and the lines between the nodes (an
evolved packet core (EPC) 3 and next generation core (NextGen core)
4) illustrate the corresponding interfaces which are under
discussion in 3GPP. Further, FIGS. 2A-2D illustrate deployment
scenarios with NR BS which are discussed in 3GPP. For example, FIG.
2A shows a non-centralized configuration where a core 5 serves
separately located NR BS 2 and an LTE eNB 1. FIG. 2B shows a
configuration where a NR BS 2 is collocated with an eNB 1. FIG. 2C
is a configuration where the NR BS 2 is divided into an upper layer
2-A and lower layers 2-B. FIG. 2D is a configuration where cores
5-A, 5-B and 5-C are operated by different operators such that
different operators share gNBs 2.
[0004] NR Numerology
[0005] For LTE, the term "numerology" includes, e.g., the following
elements: frame duration, subframe or transition time interval
(TTI) duration, slot duration, subcarrier spacing, number of
subcarriers per resource block (RB), number of RBs within the
bandwidth (different numerologies may result in different numbers
of RBs within the same bandwidth).
[0006] The exact values for the numerology elements in different
radio access technologies (RATs) are typically driven by
performance targets, e.g., performance requirements impose
constraints on usable subcarrier spacing sizes, e.g., the maximum
acceptable phase noise and the slow decay of the spectrum
(impacting filtering complexity and guardband sizes) set the
minimum subcarrier bandwidth for a given carder frequency, and the
required cyclic prefix sets the maximum subcarrier bandwidth for a
given carrier frequency.
[0007] However, the numerology used so far in the existing RATs is
rather static and typically can be trivially derived by the
wireless device (e.g., User Equipment (UE)), e.g., by one-to-one
mapping to RAT, frequency band, service type (e.g., multimedia
broadcast multicast services (MBMS)), etc.
[0008] In LTE downlink which is orthogonal frequency-division
multiplexing (OFDM)-based, the subcarrier spacing is 15 kHz for
normal cycle prefix (CP) and 15 kHz and 7.5 kHz (i.e., the reduced
carrier spacing) for extended CP, where the latter is allowed only
for MBMS-dedicated carriers.
[0009] The support of multiple numerologies has been agreed for NR,
which can be multiplexed in the frequency and/or time domain for
the same or different wireless devices.
[0010] In NR, which is to be based on OFDM, multiple numerologies
will be supported for general operation. A scaling approach (based
on a scaling factor 2{circumflex over ( )}n, n=1, 2, . . . ) is
considered for deriving subcarrier spacing candidates for NR: 15
kHz, 30 kHz, 60 kHz, etc. The numerology-specific subframe
durations can then be determined in ms based on the subcarrier
spacing: subcarrier spacing of (2.sup.m*15) kHz gives exactly
1/2.sup.m ms.
[0011] Subcarrier spacings of up to 960 kHz are currently being
discussed for NR (the highest discussed values correspond to
millimeter-wave based technologies). It was also agreed that
multiplexing different numerologies within a same NR carrier
bandwidth is supported, and frequency division multiplexing (FDM)
and/or time division multiplexing (TDM) can be considered. It was
further agreed that multiple frequency/time portions using
different numerologies share a synchronization signal, where the
synchronization signal refers to the signal itself and the
time-frequency resource used to transmit the synchronization
signal. Yet another agreement is that the numerology used can be
selected independently of the frequency band although it is assumed
that a very low subcarrier spacing will not be used at very high
carrier frequencies. In FIG. 3, some candidate carrier spacings are
illustrated with respect to the frequency and cell range. In Table
1 below, further details are provided on corresponding time
durations for some candidate carrier spacings.
[0012] In multicarrier or carrier aggregation (CA) operation, the
wireless device is able to receive and/or transmit data to more
than one serving cell. The term carrier aggregation (CA) is also
called (e.g., interchangeably called) "multi-carrier system,"
"multi-cell operation," "multi-carrier operation," "multi-carrier"
transmission and/or reception. In CA, one of the component carriers
(CCs) is the primary component carrier (PCC) or simply primary
carrier or even anchor carrier. The remaining ones are called
secondary component carriers (SCC) or simply secondary carriers or
even supplementary carriers. The serving cell is interchangeably
called a primary cell (PCell) or primary serving cell (PSC).
Similarly, the secondary serving cell is interchangeably called a
secondary cell (SCell) or secondary serving cell (SSC).
[0013] In Dual Connectivity (DC) operation, the wireless device can
be served by at least two nodes; one called the master eNB (MeNB)
and another called the secondary eNB (SeNB). Generally, in multiple
connectivity (aka multi-connectivity) operation, the wireless
device can be served by two or more nodes, e.g., MeNB, SeNB1, SeNB2
and so on. The wireless device is configured with PCC from both
MeNB and SeNB. The PCell from MeNB and SeNB are called as PCell and
PSCell respectively. The PCell and PSCell operate the wireless
device typically independently. The wireless device is also
configured with one or more SCCs from each of MeNB and SeNB. The
corresponding secondary serving cells served by MeNB and SeNB are
called SCells. The wireless device in DC typically has separate
transmitter (TX)/receiver (RX) for each of the connections with
MeNB and SeNB. This allows the MeNB and SeNB to independently
configure the wireless device with one or more procedures e.g.
radio link monitoring (RLM), Discontinuous Reception (DRX) cycle
etc. on their PCell and PSCell respectively. The methods and
embodiments are applicable to both CA, DC and Multi-Connectivity
(MC).
[0014] The term "signaling" used herein may comprise any of:
high-layer signaling (e.g., via Radio Resource Control (RRC) or the
like), lower-layer signaling (e.g., via a physical control channel
or a broadcast channel), or a combination thereof. The signaling
may be implicit or explicit. The signaling may further be unicast,
multicast or broadcast. The signaling may also be directly to
another node or via a third node.
[0015] The term time resource used herein may correspond to any
type of physical resource or radio resource expressed in terms of
length of time. Examples of time resources are: symbol, time slot,
subframe, radio frame, transmission time interval (TTI),
interleaving time, etc.
[0016] The term "flexible numerology" used herein may refer, e.g.,
to any one or more of: subcarrier spacing, number of subcarriers
per RB, number of RBs within the bandwidth, etc. which can be
configured in a flexible way and may be changed dynamically.
[0017] The term "radio measurement" used herein may refer to any
measurement performed on radio signals. Radio measurements can be
absolute or relative. Radio measurements can be e.g.
intra-frequency, inter-frequency, CA, etc. Radio measurements can
be unidirectional (e.g., downlink (DL) or uplink (UL)) or
bidirectional (e.g., round-trip time (RTT), Rx-Tx, etc.). Some
examples of radio measurements: timing measurements (e.g., time of
arrival (TOA), timing advance, RTT, Reference Signal Time
Difference (RSTD), SSTD, Rx-Tx, propagation delay, etc.), angle
measurements (e.g., angle of arrival), power-based measurements
(e.g., received signal power, reference signal received power
(RSRP), received signal quality, reference signal received quality
(RSRQ), signal-to-interference-plus-noise ratio (SINR),
signal-to-noise ratio (SNR), channel state information (CSI),
channel quality information (CQI), precoding matrix indicator
(PMI), interference power, total interference plus noise, received
signal strength indicator (RSSI), noise power, etc.), cell
detection or identification, beam detection or beam identification,
system information reading, radio link monitoring (RLM), etc.
[0018] Multicarrier Operation
[0019] In carrier aggregation (CA), the terminal is configured with
a PCC (or cell or Serving cell) which is referred to as the Primary
Cell (PCell). The PCell is particularly important e.g. due to the
fact that the control signaling is signaled on this cell etc. Also,
the wireless device performs monitoring of the radio quality on the
PCell. A CA capable terminal can, as explained above, also be
configured with additional carriers (or cells or serving cells)
which are referred to as Secondary Cells (SCells).
[0020] In dual connectivity (DC), a wireless device in an
RRC_CONNECTED state is configured with a Master Cell Group (MCG)
and a Secondary Cell Group (SCG). Cell Group (CG) is a group of
serving cells associated with either the MeNB or the SeNB,
respectively. The MCG and SCG are defined as follows: MCG is a
group of serving cells associated with the MeNB, comprising the
PCell and, optionally, one or more SCells. SCG is a group of
serving cells associated with the SeNB comprising the pSCell
(Primary SCell) and, optionally, one or more SCells.
[0021] The serving cell management is performed by means of media
access control (MAC) commands to control (de)configuration of
SCell(s) (aka SCell addition), (de)activation of SCell(s), and
setting up and releasing PSCell in DC. The PCell is always
activated, while SCell can be activated or deactivated.
[0022] Multiple Tags
[0023] A wireless device configured with CA, is configured with at
least one Timing Advance Group (TAG) which is a pTAG containing
PCell. The pTAG may also contain one or more SCells.
[0024] The wireless device capable of supporting multiple timing
advances may also be configured with one or more serving cells with
uplink in one or more sTAGs, in addition to pTAG.
[0025] The wireless device capable of supporting dual connectivity
shall be configured with one pTAG and may also be configured with
one psTAG. The pTAG shall contain the PCell and may also contain
one SCell, if configured. The psTAG shall contain the PSCell and
may also contain one SCell, if configured. In pTAG, the wireless
device shall use the PCell as the reference cell for deriving the
wireless device transmit timing for pTAG, and in psTAG, the
wireless device shall use the PSCell as the reference cell for
deriving the wireless device transmit timing for psTAG.
[0026] Cells in the same TAG can share the same reference timing.
Furthermore, if at least one serving cell of the TAG is uplink time
aligned, all serving cells belonging to the same group may use this
timing adjustment value.
[0027] The TAGs are configured by the eNodeB. Each sTAG has
associated sTAG ID and a time alignment timer (TAT). The TAT starts
when a serving cell of the TA group performs random access and is
thereby assigned its first TA value. The TAT is then restarted each
time the TA value used by the TA group is updated, e.g., upon
reception of a TA command (TAC). A SCell is considered uplink time
aligned when the associated TAT is running and it may then, if
activated, transmit on the wireless device. When the TAT expires,
the serving cells associated with that TAT may not perform any
wireless device transmission except for random access request.
[0028] Synchronized and Unsynchronized Dual Connectivity
Operation
[0029] In DC, the handling of the maximum received timing
difference (.DELTA.t) of the signals from MeNB and SeNB received at
the wireless device depends on wireless device architecture. This
gives rise to two cases of dual connectivity (DC) operation with
respect to the wireless device synchronization status or level
namely: synchronized DC operation and unsynchronized DC operation.
The synchronized DC operation and unsynchronized DC operation are
also interchangeably called synchronous and asynchronous DC.
[0030] The synchronized operation herein means that the wireless
device can perform DC operation provided the received time
difference (.DELTA.t) between the signals received at the wireless
device from the CCs belonging to the MCG and SCG are within a
certain threshold e.g. .+-.33 .mu.s. As an example, the
synchronized operation herein means that the received time
difference (.DELTA.t) between the signals received at the wireless
device from the subframe boundaries of the CCs belonging to the MCG
and SCG are within a certain threshold e.g. .+-.33 .mu.s.
[0031] The unsynchronized operation herein means that the wireless
device can perform DC operation regardless of the received time
difference (.DELTA.t) between the signals received at the wireless
device from the CCs belonging to the MCG and SCG i.e. for any value
of .DELTA.t. As an example, the unsynchronized operation herein
means that the received time difference (.DELTA.t) between the
signals received at the wireless device from the subframe
boundaries of the CCs belonging to the MCG and SCG can be any value
e.g. more than .+-.33 .mu.s, any value up to .+-.0.5 ms etc.
[0032] Furthermore, the wireless device is also capable of handling
a maximum uplink transmission timing difference between PCell and
PSCell of at least [0033] 35.21 .mu.s if the wireless device is
capable of synchronous dual connectivity and [0034] Up to 500 .mu.s
if the wireless device is capable of asynchronous dual
connectivity
[0035] Maximum receive timing difference (.DELTA.t) at the wireless
device includes the following components:
[0036] (1) Relative propagation delay, which is expressed as the
difference of propagation delay between MeNB and SeNB;
[0037] (2) Tx timing difference due to synchronization levels
between antenna connectors of MeNB and SeNB; and
[0038] (3) Delay due to multipath propagation of radio signals from
each of the eNBs.
[0039] The wireless device signals its capability to the network
node indicating whether the wireless device is capable of
synchronized and/or unsynchronized dual connectivity operation. The
capability information is associated with each band or band
combination supported by the wireless device for dual connectivity
operation e.g. the wireless device may indicate it supports
synchronized and unsynchronized DC operations for frequency band
combinations: band 1+band 3 and band 7+band 8, respectively. Based
on this received wireless device capability information the network
node can determine whether the wireless device should be configured
in synchronized or unsynchronized DC operation for a particular
band or band combination.
SUMMARY
[0040] In NR, different numerologies can be used in different time
resources of the same link or on different links involved in an
operation. Examples of operations are multicarrier operation,
positioning measurements performed over two or more links or cells
e.g. received time difference. The multi-connectivity operation of
the wireless device can be synchronous or asynchronous. Also, the
positioning measurements can be performed on pair of cells which
can be synchronous or asynchronous. However, the impact of
different numerology on such operations (e.g. multi-connectivity
operation) is undefined. In particular, the impact on the
synchronization status of the wireless device under different
possible numerologies is unknown. Due to these limitations and
undefined principles, operations such as the multi-connectivity
operation in the NR and/or positioning cannot be performed or at
least the performance of these operations will be severely
degraded.
[0041] Certain embodiments of aspects of the present disclosure may
provide one or more technical advantages, including: [0042] The
multi-connectivity operation involving different numerologies is
enhanced. [0043] Synchronization status of the wireless device
under multi-connectivity operation involving different numerologies
is well defined.
[0044] Certain embodiments may have some, all or none of the above
advantages. Other advantages will be apparent to persons of
ordinary skill in the art.
[0045] Some embodiments include a method performed by a wireless
device for determining a synchronization status for the wireless
device based on a first numerology and a second numerology. The
method includes estimating a time difference between receipt of a
first downlink signal received from a first network node and
receipt of a second downlink signal received from a second network
node. The method further includes obtaining a first downlink
threshold based on the first numerology and the second numerology.
The method also includes determining the synchronization status of
the wireless device based on a comparison between the estimated
time difference and the first downlink threshold.
[0046] According to another aspect, some embodiments include a
wireless device configured to determine a synchronization status
for the wireless device based on a first numerology and a second
numerology. The wireless device includes a communications
interface. The wireless device also includes processing circuitry
configured to estimate a time difference between receipt of a first
downlink signal received from a first network node, and receipt of
a second downlink signal received from a second network node. The
processing circuitry is also configured to obtain a first downlink
threshold based on the first numerology and the second numerology.
The processing circuitry is also configured to determine the
synchronization status of the wireless device based on a comparison
between the estimated time difference and the first downlink
threshold.
[0047] In some embodiments, a method performed by a network node
for determining a synchronization status for a wireless device
based on a first numerology and a second numerology is provided.
The method includes obtaining, from the wireless device, an
estimated time difference between receipt, by the wireless device
of a first downlink signal received from a first network node, and
receipt, by the wireless device of a second downlink signal
received from a second network node. The method further includes
obtaining a first downlink threshold based on the first numerology
and the second numerology. The method also includes determining the
synchronization status of the wireless device based on a comparison
between the estimated time difference and the first downlink
threshold. In some embodiments, a network node configured to
determine a synchronization status for a wireless device based on a
first numerology and a second numerology is provided. The network
node includes a communications interface configured to: obtain,
from the wireless device, an estimated time difference between
receipt, by the wireless device of a first downlink signal received
from a first network node, and receipt, by the wireless device of a
second downlink signal received from a second network node; and
obtain a first downlink threshold based on the first numerology and
the second numerology. The network node also includes processing
circuitry configured to determine the synchronization status of the
wireless device based on a comparison between the estimated time
difference and the first downlink threshold.
[0048] In some embodiments, a method performed by a wireless device
for determining a synchronization status for the wireless device
based on a first numerology and a second numerology. The method
includes estimating a time difference between a transmission time
of a first uplink signal transmitted by the wireless device and a
transmission time of a second uplink signal transmitted by the
wireless device. The method also includes obtaining a first uplink
threshold based on the first numerology and the second numerology.
The method further includes determining the synchronization status
of the wireless device based on a comparison between the estimated
time difference and the first uplink threshold.
[0049] In some embodiments, a wireless device configured to
determine a synchronization status for the wireless device based on
a first numerology and a second numerology is provided. The method
includes processing circuitry configured to estimate a time
difference between transmission of a first uplink signal
transmitted by the wireless device and transmission of a second
uplink signal transmitted by the wireless device. The processing
circuitry is also configured to obtain a first uplink threshold
based on the first numerology and the second numerology and
determine the synchronization status of the wireless device based
on a comparison between the estimated time difference and the first
uplink threshold.
[0050] In some embodiments, a method performed by a network node
for determining a synchronization status for a wireless device
based on a first numerology and a second numerology is provided.
The method includes obtaining, from the wireless device, an
estimated time difference between transmission of a first uplink
signal and transmission of a second uplink signal. The method also
includes obtaining a first uplink threshold based on the first
numerology and the second numerology. The method also includes
determining the synchronization status of the wireless device based
on a comparison between the estimated time difference and the first
uplink threshold.
[0051] In some embodiments, a network node configured to determine
a synchronization status for a wireless device based on a first
numerology and a second numerology is provided. The network node
includes processing circuitry configured to obtain, from the
wireless device, an estimated time difference between transmission
of a first uplink signal and transmission of a second uplink
signal. The processing circuitry is further configured to obtain a
first uplink threshold based on the first numerology and the second
numerology, and determine the synchronization status of the
wireless device based on a comparison between the estimated time
difference and the first uplink threshold.
[0052] In some embodiments, a method performed by a wireless device
for determining a synchronization status for the wireless device
based on a first numerology and a second numerology defined for
data transmission is provided. The method includes estimating a
transmission time difference between a first signal and a second
signal exchanged between the wireless device and a first network
node and a second network node, respectively. The method also
includes obtaining a threshold based on the first numerology and
the second numerology. The method also includes determining the
synchronization status of the wireless device based on a comparison
between the estimated transmission time difference and the
threshold.
[0053] In some embodiments, a wireless device for determining a
synchronization status for the wireless device based on a first
numerology and a second numerology defined for data transmission is
provided. The wireless device includes processing circuitry
configured to estimate a transmission time difference between a
first signal and a second signal exchanged between the wireless
device and a first network node and a second network node,
respectively. The processing circuitry is also configured to obtain
a threshold based on the first numerology and the second
numerology, and determine the synchronization status of the
wireless device based on a comparison between the estimated
transmission time difference and the threshold.
[0054] In some embodiments, a method performed by a network node
for determining a synchronization status for a wireless device
based on a first numerology and a second numerology defined for
data transmission is provided. The method includes obtaining, from
the wireless device, an estimated transmission time difference
between a first signal and a second signal exchanged between the
wireless device and a first network node and a second network node
respectively, obtaining a threshold based on the first numerology
and the second numerology and determining the synchronization
status of the wireless device based on a comparison between the
estimated transmission time difference and the threshold.
BRIEF DESCRIPTION OF THE DRAWINGS
[0055] A more complete understanding of the present embodiments,
and the attendant advantages and features thereof, will be more
readily understood by reference to the following detailed
description when considered in conjunction with the accompanying
drawings wherein:
[0056] FIG. 1 is an illustration of an NR architecture;
[0057] FIGS. 2-2D are an illustration of deployment scenarios with
NR base stations;
[0058] FIG. 3 is an illustration of example subcarrier spacing
candidate configurations for NR;
[0059] FIG. 4 illustrates an exemplary wireless device for
determining a synchronization status for the wireless device based
on a first numerology and a second numerology in accordance with
the principles described herein;
[0060] FIG. 5 is a flowchart of an exemplary process performed by a
wireless device for determining a synchronization status for the
wireless device based on a first numerology and a second numerology
in accordance with the principles described herein;
[0061] FIG. 6 illustrates an exemplary network node for determining
a synchronization status for the wireless device based on a first
numerology and a second numerology in accordance with the
principles described herein;
[0062] FIG. 7 is a flowchart of an exemplary process performed by a
network node for determining a synchronization status for the
wireless device based on a first numerology and a second numerology
in accordance with the principles described herein;
[0063] FIG. 8 illustrates another exemplary wireless device for
determining a synchronization status for the wireless device based
on a first numerology and a second numerology in accordance with
the principles described herein;
[0064] FIG. 9 illustrates another exemplary network node for
determining a synchronization status for the wireless device based
on a first numerology and a second numerology in accordance with
the principles described herein;
[0065] FIG. 10 is a flowchart of another exemplary process
performed by a wireless device for determining a synchronization
status for the wireless device based on a first numerology and a
second numerology;
[0066] FIG. 11 is a flowchart of another exemplary process
performed by a network node for determining a synchronization
status for a wireless device based on a first numerology and a
second numerology;
[0067] FIG. 12 is a flowchart of another exemplary process
performed by a wireless device for determining a synchronization
status for the wireless device based on a first numerology and a
second numerology; and
[0068] FIG. 13 is a flowchart of an exemplary process performed by
a network node for determining a synchronization status of a
wireless device.
DETAILED DESCRIPTION
[0069] Note that although terminology from the third generation
partnership project (3GPP), i.e., long term evolution (LTE) is used
in this disclosure as an example, this should not be seen as
limiting the scope of the disclosure to only the aforementioned
system. Other wireless systems, including NR (i.e., 5G), wideband
code division multiple access (WCDMA), WiMax, ultra mobile
broadband (UMB) and global system for mobile communications (GSM),
may also benefit from exploiting the concepts and methods covered
within this disclosure.
[0070] Also note that terminology such as eNodeB and wireless
device should be considered non-limiting and does in particular not
imply a certain hierarchical relation between the two; in general
"eNodeB" could be considered as device 1 and "wireless device"
device 2, and these two devices communicate with each other over
some radio channel. Also, while the disclosure focuses on wireless
transmissions in the downlink, embodiments are equally applicable
in the uplink.
[0071] The term "wireless device" used herein may refer to any type
of wireless device communicating with a network node and/or with
another wireless device in a cellular or mobile communication
system. Examples of a wireless device are user equipment (UE),
target device, device to device (D2D) wireless device, machine type
wireless device or wireless device capable of machine to machine
(M2M) communication, a sensor equipped with UE, PDA, iPAD, Tablet,
mobile terminals, smart phone, laptop embedded equipped (LEE),
laptop mounted equipment (LME), USB dongles, computer premises
equipment (CPE), etc.
[0072] The term "network node" used herein may refer to a radio
network node or another network node, e.g., a core network node,
MSC, MME, O&M, OSS, SON, positioning node (e.g. E-SMLC), MDT
node, etc.
[0073] The term "network node" or "radio network node" used herein
can be any kind of network node comprised in a radio network which
may further comprise any of base station (BS), radio base station,
base transceiver station (BTS), base station controller (BSC),
radio network controller (RNC), g Node B (gNB), evolved Node B (eNB
or eNodeB), Node B, multi-standard radio (MSR) radio node such as
MSR BS, multi-cell/multicast coordination entity (MCE), relay node,
donor node controlling relay, radio access point (AP), transmission
points, transmission nodes, Remote Radio Unit (RRU) Remote Radio
Head (RRH), a core network node (e.g., mobile management entity
(MME), self-organizing network (SON) node, a coordinating node,
positioning node, MDT node, etc.), an external node (e.g., 3.sup.rd
party node, a node external to the current network), nodes in
distributed antenna system (DAS) etc. The network node may also
comprise test equipment. The term "radio node" used herein may be
used to also denote a wireless device such as a UE or a radio
network node.
[0074] Note further, that functions described herein as being
performed by a wireless device or a network node may be distributed
over a plurality of wireless devices and/or network nodes. In other
words, it is contemplated that the functions of the network node
and wireless device described herein are not limited to performance
by a single physical device and, in fact, can be distributed among
several physical devices.
[0075] Before describing in detail exemplary embodiments, it is
noted that the embodiments reside primarily in combinations of
apparatus components and processing steps related to adaptation
between synchronous and asynchronous operations in a wireless
network based on numerology. Accordingly, components have been
represented where appropriate by conventional symbols in the
drawings, showing only those specific details that are pertinent to
understanding the embodiments so as not to obscure the disclosure
with details that will be readily apparent to those of ordinary
skill in the art having the benefit of the description herein.
[0076] As used herein, relational terms, such as "first" and
"second," "top" and "bottom," and the like, may be used solely to
distinguish one entity or element from another entity or element
without necessarily requiring or implying any physical or logical
relationship or order between such entities or elements.
[0077] In some embodiments, the present disclosure provides a
wireless device that indicates to another node, information about
the wireless device capability related to the support of
synchronous and/or asynchronous operation (e.g. multi-connectivity,
carrier aggregation, positioning etc.). In one embodiment, this
step is an optional step in the process. In a next step, the
wireless device estimates a receive time difference (.DELTA.Tr)
between a first downlink signal (DLS1) received at the wireless
device from a first network node (NW1) and a second downlink signal
(DLS2) received at the wireless device from a second network node
(NW2). In one embodiment, NW1 and NW2 may be the same. In another
embodiment, NW1 and NW2 may be different.
[0078] In a next step, the wireless device determines at least one
first numerology (N1) and at least one second numerology (N2) used
for operating DLS1 and DLS2 respectively. In a next step, the
wireless device obtains a first downlink threshold (G1) based on
the determined N1 and N2. In a next step, the wireless device
determines a synchronization status of the wireless device based on
a relation between .DELTA.Tr and G1. Optionally, the wireless
device may use the determined synchronization status of the
wireless device for one or more operational tasks.
[0079] The following describes each of the steps presented above in
greater detail. In the first (optional) step, the wireless device
may indicate to another node (e.g., a network node, e.g., radio
network node, core network node, positioning node, etc.)
information about the wireless device's capability related to the
support of synchronous and/or asynchronous multi-connectivity. The
indicated wireless device capability may further include capability
of the wireless device to operate synchronous and/or asynchronous
multi-connectivity under the flexible numerology scenario. The
capability may be sent upon a request from another node (i.e., a
network node such as an eNB) or in an unsolicited way, e.g., upon a
triggering event, condition, or in response to receiving a message
from another node, etc.
[0080] In the next step, the wireless device estimates a time
difference (.DELTA.Tr) between a first downlink signal (DLS1)
received at the wireless device from a first network node (NW1) and
a second downlink signal (DLS2) received at the wireless device
from a second network node (NW2). The DLS1 and DLS2 may be received
in a first cell (cell1) and a second cell (cell2). Cell1 and cell2
are operated by NW1 and NW2 respectively. Cell1 and cell2 may also
be serving cells of the wireless device. In one example, NW1 and
NW2 are the same node. In another example, NW1 and NW2 are
different nodes and may be co-sited, co-located or non-collocated.
The estimation of .DELTA.Tr may be performed over an estimation
time period (Td), which may include one or multiple time resources
(e.g. one subframe or plurality of subframes). The estimation of
.DELTA.Tr may further include one or a plurality of samples or
snapshots obtained by the wireless device within Td.
[0081] The term estimation herein may interchangeably be called a
calculation, measurement or determination. Similarly, the
estimation time period may interchangeably be called a measurement
time period, calculation time period, etc.
[0082] The estimation of .DELTA.Tr may be performed between
boundaries of specific time resources. The specific time resources
may be, e.g., one or more of [0083] a certain type (e.g.,
subframe); [0084] determined based on a pre-defined rule while
accounting for the used numerology (e.g., between a time resource
associated with DLS1 and the closest time resource with a number or
ID meeting a condition [e.g. an even number or mod(ID,n)=0 where n
is an integer e.g. n=2] associated with DLS2 when the subcarrier
spacing for DLS1 is smaller than that for DLS2); and [0085]
determined based on an indication or message received from another
node, etc.
[0086] The time resources (e.g., subframes or slots) may be of the
same absolute length (but e.g. different time resource granularity
within the subframes, due to different numerologies) or different
absolute lengths.
[0087] For example, .DELTA.Tr may be estimated by the wireless
device between the start of the DL subframes of NW1 and NW2
transmitting DLS1 and DLS2 respectively. In another example
.DELTA.Tr may be estimated by the wireless device between the start
of the DL frames of NW1 and NW2 transmitting DLS1 and DLS2
respectively.
[0088] The wireless device may further estimate a transmit time
difference (.DELTA.Tt) between a first uplink signal (ULS1)
transmitted by the wireless device in a first cell (cell1) operated
by a first network node (NW1) and a second uplink signal (DLS2)
transmitted by the wireless device in a second cell (cell2)
operated by a second network node (NW2). The ULS1 and ULS2 may be
transmitted in a first cell (cell1) and a second cell (cell2). In
another example ULS1 and ULS2 may be transmitted by the wireless
device in another set of cells, a third cell (cell3) and a fourth
cell (cell4). Cell3 and cell4 may also be operated by NW1 and NW2
respectively. Cell3 and cell4 may also be serving cells of the
wireless device. The value of .DELTA.Tt may be estimated between
the starting boundaries of time resources (e.g. slot or subframe
etc.) belonging to cell3 and cell4 respectively. The value of
.DELTA.Tt may also be called a time difference between TAGs i.e.
between TAG1 and TAG2 which contains cell3 and cell4
respectively.
[0089] The estimation of .DELTA.Tt may be performed over an
estimation time period (Tu), which may include one or multiple time
resources (e.g. one subframe or plurality of subframes). The
estimation of .DELTA.Tt may further include one or a plurality of
samples or snapshots obtained by the wireless device within Tu.
[0090] Cell1 and cell2 may be operated using carrier frequency #1
(F1) and carrier frequency #2 (F2) respectively.
[0091] Cell1 and cell2 may also be operated using carrier frequency
#1 (F1) and carrier frequency #2 (F2) respectively in the DL and
using carrier frequency #3 (F3) and carrier frequency #4 (F4)
respectively.
[0092] In one exemplary implementation, F1 and F2 may be the same.
In another exemplary implementation F1 and F2 may be different.
[0093] In one exemplary implementation, F3 and F4 may be the same.
In another exemplary implementation F3 and F4 may be different.
[0094] The DLS1 and DLS2 may be transmitted by NW1 and NW2
respectively using numerology #1 (N1) and numerology #2 (N2)
respectively.
[0095] The ULS1 and ULS2 may also be transmitted by the wireless
device using numerology #1 (N1) and numerology #2 (N2)
respectively.
[0096] In yet another example, ULS1 and ULS2 may be transmitted by
the wireless device using numerology #3 (N3) and numerology #4 (N4)
respectively.
[0097] In one exemplary implementation, N1 and N2 may be the same.
In another exemplary implementation N1 and N2 may be different.
[0098] Also in one exemplary implementation, N3 and N4 may be the
same. In another exemplary implementation, N3 and N4 may be
different.
[0099] In a next step, the wireless device may determine
information related to at least one first numerology (N1) and at
least one second numerology (N2) used for operating DLS1 and DLS2
respectively. The wireless device may further determine information
related to a plurality of numerologies used for transmitting DLS1
in the same cell or link e.g. different numerologies used in
different time resources in the same cell. The wireless device may
further determine information related to a plurality of
numerologies used for transmitting DLS2 in the same cell or link
e.g. different numerologies used in different time resources in the
same cell. The wireless device may further determine information
related to at least a third numerology (N3) and at least a fourth
numerology (N4) used for operating ULS1 and ULS2 respectively. The
wireless device may determine the numerologies based on one or more
of stored information in the wireless device, indication received
from a network node, radio measurements performed by the wireless
device etc. The information related to a numerology may include,
e.g., subcarrier spacing, time resource length, CP length, etc.
[0100] In a next step, the wireless device may determine at least a
first downlink threshold (G1) based on the determined information
about N1 and N2. The threshold G1 defines a boundary between
synchronous and asynchronous operations of the wireless device with
respect to cell1 and cell2. In some embodiments, N1 and N2 may be
the same i.e. N1=N2.
G1=f(N1,N2) (1)
[0101] The wireless device may further determine a second downlink
threshold (G2) based on the determined information about N1 and N2.
The threshold G2 defines a maximum receive time difference that the
wireless device can handle, e.g., a magnitude of the maximum
.DELTA.Tr under asynchronous operation of the wireless device.
G2=f(N1,N2) (2)
[0102] Examples of the functions are: a certain fraction (e.g.,
half) of the smallest time unit of the same type among the two
numerologies.
[0103] In the above, when two or more numerologies are used by at
least one of the NW1 and NW2, N1 and/or N2 may be selected from the
plurality or pluralities of numerologies used by NW1 and/or NW2
based on a pre-defined rule, e.g., N1 and N2, corresponding to the
numerologies with the largest subcarrier spacings in NW1 and NW2,
respectively. The same principles may apply for N3 and N4.
[0104] Examples of magnitude of G1 and G2 as a function of N1 and
N2 used in cell1 and cell2 respectively are shown in Table 1
below.
[0105] Table 1: Magnitude of thresholds, G1 and G2, as a function
of numerology used in downlink of cell1 and downlink of cell2. The
values of X1, Y1 and Z1 correspond to the magnitude of the receive
time difference that the UE can handle under synchronous operation
for different combinations of numerologies used in DL of cell1 and
DL of cell2. The values of X2, Y2 and Z2 correspond to the
magnitude of the receive time difference that the UE can handle
under asynchronous operation for different combinations of
numerologies used in DL of cell1 and DL of cell2.
TABLE-US-00001 TABLE 1 Numerology used Numerology used No. in DL of
cell1 in DL of cell2 G1 G2 1 N1 N1 X1 X2 2 N2 N2 Y1 Y2 3 N1 N2 Z1
Z2 4 N2 N1 Z1 72
[0106] Specific examples of the magnitude of G1 and G2 as a
function of subcarrier spacings used in cell1 and cell2
respectively are shown in Table 2 below. As shown in Table 2, the
larger subcarrier spacings used in the cells results in smaller
values of G1 and G2. This is because larger subcarrier spacing
leads to short time resource duration (e.g. slot, subframe etc.).
The value of .DELTA.Tr is estimated between boundaries of time
resources (e.g. between slots) leading to smaller maximum value of
G1 or G2 if the duration of the time resource (e.g. slot duration)
is also smaller.
[0107] Table 2: Magnitude of thresholds, G1 and G2, as a function
of subcarrier used in DL of cell1 and DL of cell2
TABLE-US-00002 TABLE 2 Subcarrier spacing Subcarrier spacing used
No. used in DL of cell1 in DL of cell2 G1 G2 1 15 KHz 15 KHz 33
.mu.s 500 .mu.s 2 30 KHz 30 KHz 20 .mu.s 250 .mu.s 3 15 KHz 30 KHz
30 .mu.s 250 .mu.s 4 30 KHz 15 KHz 30 .mu.s 250 .mu.s 5 60 KHz 60
KHz 10 .mu.s 125 .mu.s 6 60 KHz 15 KHz 30 .mu.s 125 .mu.s
[0108] The wireless device may further determine a first uplink
threshold (H1) based on the determined information about N3 and N4
used in wireless device of cell1 and cell2 respectively. In some
embodiments, N3 and N4 may be N1 and N2 respectively. In some
embodiments, N3 and N4 may be the same, i.e., N3=N4.
[0109] The threshold H1 defines a maximum value of uplink transmit
time difference (.DELTA.Tt) between a first TA group (TAG1) and a
second TA group (TAG2) for synchronous operation of the wireless
device with respect to cell1 and cell2 in the uplink. Cell1 and
cell2 belong to TAG1 and TAG2 respectively. The .DELTA.Tt is also
known as the maximum uplink transmission timing difference between
cell1 and cell2, e.g., between PCell and PSCell.
H1=f(N3,N4) (3)
[0110] The wireless device may further determine a second uplink
threshold (H2) based on the determined information about N3 and N4.
The threshold H2 defines a maximum value of uplink transmit time
difference between a first TA group (TAG1) and a second TA group
(TAG2) for asynchronous operation of the wireless device with
respect to cell1 and cell2, e.g., magnitude of the maximum
.DELTA.Tt under asynchronous operation of the wireless device
H2=f(N3,N4) (4)
[0111] Examples of magnitude of H1 and H2 as function of N3 and N4
used in the wireless device of cell1 and UL of cell2 respectively
are shown in Table 3 below.
[0112] Table 3: Magnitude of thresholds, H1 and H2, as a function
of numerology used in uplink of cell1 and uplink of cell2. The
values of A1, B1 and C1 correspond to the magnitude of the uplink
transmit time difference between the TAGs that the UE can handle
under synchronous operation for different combinations of
numerologies used in DL of cell1 and DL of cell2. The values of A2,
B2 and C2 correspond to the magnitude of the uplink transmit time
difference between the TAGs that the UE can handle under
asynchronous operation for different combinations of numerologies
used in DL of cell1 and DL of cell2.
TABLE-US-00003 TABLE 3 Numerology used Numerology used No. in UL of
cell1 in a of cell2 H1 H2 1 N3 N3 A1 A2 2 N4 N4 B1 B2 3 N3 N4 C1 C2
4 N4 N3 C1 C2
[0113] Specific examples of magnitude of H1 and H2 as a function of
subcarrier spacings used by the wireless device for UL transmission
in cell1 and for UL transmission in cell2 respectively are shown in
Table 4 below. As shown in Table 4, the larger subcarrier spacings
used in the cells results in smaller values of H1 and H2. The value
of .DELTA.Tt is estimated between boundaries of time resources
(e.g. between slots) leading to smaller maximum value of H1 or H2
if the duration of the time resource (e.g. slot duration) is also
smaller.
[0114] Table 4: Magnitude of thresholds, H1 and H2, as a function
of subcarriers used by the wireless device for UL transmission in
cell1 and for UL transmission in cell2 TABLE 4
TABLE-US-00004 TABLE 4 Subcarrier spacing Subcarrier spacing No.
used in UL of cell1 used in UL of cell2 H1 H2 1 15 KHz 15 KHz 35.21
.mu.s 500 .mu.s 2 30 KHz 30 KHz 25 .mu.s 250 .mu.s 3 15 KHz 30 KHz
30 .mu.s 250 .mu.s 4 30 KHz 15 KHz 30 .mu.s 250 .mu.s 5 60 KHz 60
KHz 15 .mu.s 125 .mu.s 6 60 KHz 15 KHz 30 .mu.s 125 .mu.s
[0115] The wireless device can determine any of the threshold
parameters G1, G2, H1 and H2 based on one or more of the following
mechanisms: [0116] Pre-defined rule e.g. pre-defined mapping tables
1, 2, 3, 4; [0117] Information received from a node, e.g., from
another wireless device and/or from a network node; [0118] History
or statistics; [0119] Recently used values, e.g., recent values
stored in the memory of the wireless device.
[0120] In another step, the wireless device may compare the
estimated value of .DELTA.Tr with the determined value of at least
G1 and based on this comparison the wireless device determines the
synchronization status of the wireless device operation with
respect to cell1 and cell2. The synchronization status may indicate
whether the wireless device is in synchronous state or in
asynchronous state with respect to cell1 and cell2. For example,
the wireless device may determine that: [0121] the wireless device
is operating in synchronous mode if the magnitude of .DELTA.Tr is
not larger than the magnitude of G1, [0122] Otherwise (i.e.
.DELTA.Tr>G1) the wireless device is operating in asynchronous
mode.
[0123] If the wireless device is determined to be operating in
asynchronous mode, then the wireless device may further ensure that
the magnitude of the maximum value of .DELTA.Tt does not exceed
G2.
[0124] If the wireless device operates in synchronous mode as
determined above, then the wireless device may further compare the
estimated value of .DELTA.Tt with the determined value of at least
H1 to ensure that the wireless device is able to handle the maximum
possible value of .DELTA.Tt under synchronous operation.
[0125] If the wireless device operates in asynchronous mode as
determined above, then the wireless device may further compare the
estimated value of .DELTA.Tt with the determined value of at least
H2 to ensure that the wireless device is able to handle the maximum
possible value of .DELTA.Tt under asynchronous operation.
[0126] In another step, which may be an optional step for the
wireless device, the wireless device uses the determined
synchronization status of the wireless device for one or more
operational tasks. Examples of such operational tasks are: [0127]
Reception of signals e.g. demodulation; [0128] Transmission of
signals e.g. ACK/NACK, CSI, etc.; [0129] Radio measurements; [0130]
Selection and application of power control scheme, etc.; [0131]
Transmitting the results of .DELTA.Tr and/or .DELTA.Tt to another
wireless device; [0132] Transmitting the results of .DELTA.Tr
and/or .DELTA.Tt to a network node e.g. serving network node, core
network node, positioning node, etc.; [0133] Indicating the
synchronization status of the wireless device to another node or
another wireless device.
[0134] In some embodiments, a network node performs a method that
includes obtaining information about wireless device capability
related to the support of synchronous and/or asynchronous
multi-connectivity. This is an optional step performed by the
network node. In another step, the network node receives a receive
time difference (.DELTA.Tr), where the .DELTA.Tr is estimated by
the wireless device between a first downlink signal (DLS1) received
at the wireless device from a first network node (NW1) and a second
downlink signal (DLS2) received at the wireless device from a
second network node (NW2). In a next step, the network node
determines at least one first numerology (N1) and at least one
second numerology (N2) used for operating DLS1 and DLS2
respectively, and, in a next step, obtains a first downlink
threshold (G1) based on the determined N1 and N2. In another step,
the network node determines a synchronization status of the
wireless device based on a relation between .DELTA.Tr and G1, such
as a comparison between .DELTA.Tr and G1. In another step, which is
an optional step, the network node uses the determined
synchronization status of the wireless device for one or more
operational tasks.
[0135] The network node can be any of: a first network node (NW1),
a second network node (NW2), any other radio network node (e.g.
neighbor of NW1 and/or NW2) core network node etc.
[0136] The steps taken at the network node outlined above, are now
discussed in greater detail.
[0137] In one step, the network node may receive from a wireless
device information about the wireless devices' capability related
to the support of synchronous and/or asynchronous
multi-connectivity. The indicated wireless device's capability may
further include the capability of the wireless device to operate
synchronous and/or asynchronous multi-connectivity under the
flexible numerology scenario. The network node may receive the
capability information from the wireless device upon request or in
an unsolicited way, e.g., upon a triggering event, condition,
receiving a message from another node, etc.
[0138] In another step, the network node may obtain a receive time
difference (.DELTA.Tr), which is estimated by the wireless device
between a first downlink signal (DLS1) received at the wireless
device from a first network node (NW1) and a second downlink signal
(DLS2) received at the wireless device from a second network node
(NW2).
[0139] The network node may further obtain a transmit time
difference (.DELTA.Tt), estimated by the wireless device between a
first uplink signal (ULS1) transmitted by the wireless device in
cell3 and a second uplink signal (ULS2) transmitted by the wireless
device in cell4. The estimation of .DELTA.Tr and .DELTA.Tt by the
wireless device is described above in reference to the functions of
the wireless device.
[0140] The network node may obtain the values of .DELTA.Tr and
.DELTA.Tt based on one or more of the following: [0141] Indication
or report or measurement results received from the wireless device;
[0142] Indication or report or measurement results received from
another node e.g. another radio network node, core network node;
[0143] Historical data or statistics.
[0144] In another step, the network node may determine information
about a first numerology (N1) and a second numerology (N2) used for
operating DLS1 and DLS2 respectively. The network node may further
determine information related to a plurality of numerologies used
for operating DLS1 in the same cell or link e.g. different
numerologies used in different time resources in the same cell. The
network node may further determine information related to a
plurality of numerologies used for operating DLS2 in the same cell
or link e.g. different numerologies used in different time
resources in the same cell. The network node may further determine
information about at least one third numerology (N3) and at least
one fourth numerology (N4) used for operating ULS1 and ULS2
respectively.
[0145] The network node may determine the numerologies based on
configuration information sent to the wireless device by the
network node or another node e.g. NW1, NW2, etc.
[0146] In another step, the network node may determine at least a
first downlink threshold (G1) based on the determined N1 and N2
used in the DL of cell1 and DL of cell2 respectively. The network
node may further determine a second downlink threshold (G2) based
on the determined N1 and N2 used in the DL of cell1 and DL cell2
respectively.
[0147] The network node may determine at least a first uplink
threshold (H1) based on the determined N3 and N4 used in the
wireless device of cell1 and the wireless device of cell2
respectively. The network node may further determine a second
uplink threshold (H2) based on the determined N3 and N4 used in the
wireless device of cell1 and the wireless device cell2
respectively.
[0148] The network node may determine any of the threshold
parameters G1, G2, H1 and H2 based on one or more of the following
mechanisms: [0149] Pre-defined rule e.g. pre-defined mapping Tables
1, 2, 3, 4 as discussed above; [0150] Information received from
another node e.g. from another network node; [0151] History or
statistics i.e. values used in the past; [0152] Recently used
values e.g. recent values stored in the memory of the network
node.
[0153] In another step, the network node may determine the
synchronization status of the wireless device based on a relation
between the obtained value of .DELTA.Tt and the determined value of
G1. The network node may further determine whether the wireless
device is operating in synchronous mode or asynchronous mode based
on the comparison between the obtained value of .DELTA.Tt and the
determined value of G2.
[0154] The network node may also determine whether the wireless
device is able to operate with the determined maximum allowed value
of .DELTA.Tt for the synchronous mode if the wireless device is
capable of synchronous mode of operation with respect to cell1 and
cell2. The network node may further determine whether the wireless
device is able to operate with the determined maximum allowed value
of .DELTA.Tt for the asynchronous mode if the wireless device is
capable of asynchronous mode of operation with respect to cell1 and
cell2.
[0155] If the wireless device operates in synchronous mode, then
the network node may further compare the estimated value of
.DELTA.Tt with the determined value of at least H1 to determine
whether the wireless device is able to handle the maximum possible
value of .DELTA.Tt under synchronous operation.
[0156] If the wireless device operates in asynchronous mode, then
the network node may further compare the estimated value of
.DELTA.Tt with the determined value of at least H2 to determine
whether the wireless device is able to handle the maximum possible
value of .DELTA.Tt under asynchronous operation.
[0157] In another step, which is optional for the network node, the
network node uses the determined synchronization status of the
wireless device for one or more operational tasks. Examples of
operational tasks are: [0158] Reception of signals from the
wireless device e.g. demodulation; [0159] Transmission of signals
to the wireless device; [0160] Scheduling of signals in UL and/or
DL at the wireless device; [0161] Radio measurements; [0162] Timing
advance estimation; [0163] Adaptation of the configuration of
measurement gaps; [0164] Adaptation of the DRX configuration used
for the wireless device; [0165] Adaptation of measurement
configuration sent to the wireless device; [0166] Configuration of
timing advance group e.g. cell1 in TAG1 and cell2 in TAG; [0167]
Selection and configuration of power control scheme etc.; [0168]
Transmitting the results of .DELTA.Tr and/or .DELTA.Tt to another
network node e.g. neighboring network node, core network node,
positioning node etc.
[0169] FIG. 4 is an exemplary wireless device 20 for determining a
synchronization status for the wireless device 20 based on a first
numerology and a second numerology. In one embodiment, wireless
device includes processing circuitry 22, which includes memory 24
in communication with one or more processors 26. One or more
processors 26 includes a time difference estimator 28 and a
synchronization status determiner 30. Wireless device 20 also
includes communications interface 32. Memory 24 includes
instructions that, when executed by one or more processors 26,
configure the one or more processors 26, and, specifically, time
difference estimator 28, to estimate a time difference between
receipt of a first downlink signal received from a first network
node, and receipt of a second downlink signal received from a
second network node. One or more processors 26 is further
configured to obtain a first downlink threshold based on the first
numerology and the second numerology. One or more processors 26,
and, specifically, synchronization status determiner 30, is
configured to determine the synchronization status of wireless
device 20 based on a relationship between the estimated time
difference and the first downlink threshold. In addition to a
traditional one or more processors and memory, processing circuitry
22 may include integrated circuitry for processing and/or control,
e.g., one or more processors and/or one or more processor cores
and/or FPGAs (Field Programmable Gate Array) and/or ASICs
(Application Specific Integrated Circuitry).
[0170] Processing circuitry 22 may include and/or be connected to
and/or be configured for accessing (e.g., writing to and/or reading
from) memory 24, which may comprise any kind of volatile and/or
non-volatile memory, e.g., cache and/or buffer memory and/or RAM
(Random Access Memory) and/or ROM (Read-Only Memory) and/or optical
memory and/or EPROM (Erasable Programmable Read-Only Memory). Such
memory 24 may be configured to store code executable by control
circuitry and/or other data, e.g., data pertaining to
communication, e.g., configuration and/or address data of nodes,
etc. Processing circuitry 22 may be configured to control any of
the methods described herein and/or to cause such methods to be
performed, e.g., by one or more processors 26. Corresponding
instructions may be stored in the memory 24, which may be readable
and/or readably connected to the processing circuitry 22. In other
words, processing circuitry 22 may include a controller, which may
comprise a microprocessor and/or microcontroller and/or FPGA
(Field-Programmable Gate Array) device and/or ASIC (Application
Specific Integrated Circuit) device. It may be considered that
processing circuitry 22 includes or may be connected or connectable
to memory, which may be configured to be accessible for reading
and/or writing by the controller and/or processing circuitry
22.
[0171] FIG. 5 is a flowchart of an exemplary process in wireless
device 20 for determining a synchronization status for wireless
device 20 based on a first numerology and a second numerology. Such
a process may be performed, for example, by processing circuitry 22
in which, in one embodiment, memory 24 stores executable program
code that, when executed by one or more processors 26, causes the
processing circuitry 22 to perform the functions described herein.
The process optionally includes indicating, via the communications
interface 32, to another node information about a capability of a
wireless device related to support of at least one of synchronous
and asynchronous multi-connectivity (Block S100). The process
includes estimating, by one or more processors 26, and,
specifically, by time difference estimator 28 of wireless device
20, a time difference between receipt of a first downlink signal
received from a first network node, and receipt of a second
downlink signal received from a second network node (Block S110).
The process further includes obtaining, by one or more processors
26, a first downlink threshold based on the first numerology and
the second numerology (Block S120), and determining, by one or more
processors 26, and, specifically, by synchronization status
determiner 30 of wireless device 20, the synchronization status of
wireless device 20 based on a relationship between the estimated
time difference and the first downlink threshold (Block 8130). The
process optionally includes using, via the processor 26, the
determined synchronization status of the wireless device for at
least one operational task (Block S140).
[0172] In one embodiment, the first numerology is used for
operating the first downlink signal and the second numerology is
used for operating the second downlink signal. In one embodiment,
the first network node and the second network node are the same. In
one embodiment, the first network node and the second network node
are different.
[0173] In one embodiment, the at least one operational task
comprises at least one of demodulation of received signals,
transmission of signals, radio measurements, at least one of
selection and application of a power control scheme, transmission
of at least one of the estimated time difference and an uplink
transmit time difference to another wireless device, transmission
of at least one of the estimated time difference and the uplink
transmit time difference to another network node, and indicating
the synchronization status of wireless device 20 to at least one of
another network node or another wireless device. In another
embodiment, the method may further include estimating, by one or
more processors 26 of wireless device 20, a transmit time
difference between a first uplink signal transmitted by wireless
device 20 in a first cell operated by the first network node and a
second uplink signal transmitted by wireless device 20 in a second
cell operated by the second network node.
It should be noted that the one or more processors 26 in
combination with the communications interface 32 of FIG. 4 are
configured to perform the method of FIG. 5 and the above
embodiments.
[0174] FIG. 6 is an exemplary network node 34 for determining a
synchronization status for wireless device 20 based on a first
numerology and a second numerology. Network node 34 includes
processing circuitry 36, which includes memory 38 in communication
with one or more processors 40. One or more processors 40 includes
a synchronization status determiner 42. Network node 34 also
includes a communications interface 44. Communications interface 44
is configured to obtain, from wireless device 20, an estimated time
difference between receipt, by wireless device 20 of a first
downlink signal received from a first network node, and receipt, by
wireless device 20 of a second downlink signal received from a
second network node. Communications interface 44 is also configured
to obtain a first downlink threshold based on the first numerology
and the second numerology. Memory 38 includes instructions that,
when executed by one or more processors 40, configure one or more
processors 40, and, specifically, synchronization status determiner
42, to determine the synchronization status of wireless device 20
based on a relationship between the estimated time difference and
the first downlink threshold. In addition to a traditional
processor and memory, processing circuitry 36 may include
integrated circuitry for processing and/or control, e.g., one or
more processors and/or one or more processor cores and/or FPGAs
(Field Programmable Gate Array) and/or ASICs (Application Specific
Integrated Circuitry).
[0175] Processing circuitry 36 may include and/or be connected to
and/or be configured for accessing (e.g., writing to and/or reading
from) memory 38, which may comprise any kind of volatile and/or
non-volatile memory, e.g., cache and/or buffer memory and/or RAM
(Random Access Memory) and/or ROM (Read-Only Memory) and/or optical
memory and/or EPROM (Erasable Programmable Read-Only Memory). Such
memory 38 may be configured to store code executable by control
circuitry and/or other data, e.g., data pertaining to
communication, e.g., configuration and/or address data of nodes,
etc. Processing circuitry 36 may be configured to control any of
the methods described herein and/or to cause such methods to be
performed, e.g., by one or more processors 36. Corresponding
instructions may be stored in the memory 38, which may be readable
and/or readably connected to the processing circuitry 36. In other
words, processing circuitry 36 may include a controller, which may
comprise a microprocessor and/or microcontroller and/or FPGA
(Field-Programmable Gate Array) device and/or ASIC (Application
Specific Integrated Circuit) device. It may be considered that
processing circuitry 36 includes or may be connected or connectable
to memory, which may be configured to be accessible for reading
and/or writing by the controller and/or processing circuitry
36.
[0176] FIG. 7 is a flowchart of an exemplary process in network
node 34 for determining a synchronization status for wireless
device 20 based on a first numerology and a second numerology. Such
a process may be performed, for example, by processing circuitry 36
in which, in one embodiment, memory 38 stores executable program
code that, when executed by one or more processors 40, causes the
processing circuitry 36 to perform the functions described herein.
The process optionally includes obtaining information about the
capability of wireless device 20 related to support of at least one
of synchronous and asynchronous multi-connectivity (Block S150).
This step may be performed by communications interface 44 of
network node 34. In one embodiment, the information is received
from wireless device 20 in response to a request for the
information from network node 34. The process includes obtaining,
by communications interface 44, from wireless device 20, an
estimated time difference between receipt, by wireless device 20 of
a first downlink signal received from a first network node, and
receipt, by wireless device 20 of a second downlink signal received
from a second network node (Block 8160). The process further
includes obtaining, by communications interface 44, a first
downlink threshold based on the first numerology and the second
numerology (Block S170). The process further includes determining,
by one or more processors 40, and, specifically, synchronization
status determiner 42 of network node 34, the synchronization status
of wireless device 20 based on a relationship between the estimated
time difference and the first downlink threshold (Block S180). In
one embodiment, the process optionally includes the step of using
the determined synchronization status of wireless device 20 for at
least one operational task (Block S190). This step may be performed
by one or more processors 40 of network node 34.
[0177] In one embodiment, the first numerology is used for
operating the first downlink signal and the second numerology is
used for operating the second downlink signal. In one embodiment,
the first network node and the second network node are the same. In
one embodiment, the first network node and the second network node
are different.
[0178] In one embodiment, the at least one operational task
comprises at least one of reception of signal from wireless device
20, transmission of signals to wireless device 20, scheduling of at
least one of uplink and downlink signals, radio measurements,
timing advance estimation, adaptation of configuration of
measurement gaps, adaptation of the DRX configuration used for
wireless device 20, adaptation of measurement configuration sent to
wireless device 20, configuration of a timing advance group, at
least one of selection and configuration of a power control scheme,
and transmission of at least one of the estimated time difference
and an uplink transmit time difference to another network node. In
one embodiment, the process further includes obtaining, at network
node 34, a transmit time difference, estimated by wireless device
20, between a first uplink signal transmitted by wireless device in
a first cell and a second uplink signal transmitted by wireless
device 20 in a second cell. This step may be performed by
communications interface 44 of network node 34.
It should be noted that the one or more processors 40 in
combination of the communications interface 44 of FIG. 6 are
configured to carry out the method of FIG. 7 and the above
embodiments.
[0179] FIG. 8 another exemplary wireless device 46 for determining
a synchronization status for wireless device 46 based on a first
numerology and a second numerology. Wireless device 46 includes a
memory module 48, a time difference estimation module 50, and a
synchronization status determination module 52. Time difference
estimation module 50 is configured to estimate a time difference
between receipt of a first downlink signal received from a first
network node, and receipt of a second downlink signal received from
a second network node. Synchronization status determination module
52 is configured to obtain a first downlink threshold based on the
first numerology and the second numerology and determine the
synchronization status of wireless device 46 based on a
relationship between the estimated time difference and the first
downlink threshold.
[0180] FIG. 9 is another exemplary network node 54 for determining
a synchronization status for wireless device 46 based on a first
numerology and a second numerology. Network node 54 includes a
communications interface module 56 configured to obtain, from
wireless device 46, an estimated time difference between receipt,
by wireless device 46 of a first downlink signal received from a
first network node, and receipt, by wireless device 46 of a second
downlink signal received from a second network node, and obtain a
first downlink threshold based on the first numerology and the
second numerology. Network node 54 also includes a synchronization
status determination module 58 configured to determine the
synchronization status of wireless device 46 based on a
relationship between the estimated time difference and the first
downlink threshold.
[0181] FIG. 10 is a flowchart of an exemplary process performed by
a wireless device for determining a synchronization status for the
wireless device based on a first numerology and a second
numerology. The process includes estimating a time difference
between a transmission time of a first uplink signal transmitted by
the wireless device and a transmission time of a second uplink
signal transmitted by the wireless device (block S200), The process
further includes obtaining an uplink threshold based on the first
numerology and the second numerology (block S210). The process also
includes determining the synchronization status of the wireless
device based on a comparison between the estimated time difference
and the first uplink threshold.
[0182] FIG. 11 is a flowchart of an exemplary process performed by
a network node for determining a synchronization status for a
wireless device based on a first numerology and a second
numerology. The process includes obtaining, from the wireless
device, an estimated time difference between a transmission time of
a first uplink signal and a transmission time of a second uplink
signal (block S230). The process further includes obtaining an
uplink threshold based on the first numerology and the second
numerology (block S240). The process also includes determining the
synchronization status of the wireless device based on a comparison
between the estimated time difference and the first uplink
threshold (block S250).
[0183] FIG. 12 is a flowchart of an exemplary process performed by
a wireless device 20 for determining a synchronization status for
the wireless device 20 based on a first numerology and a second
numerology defined for data transmission. The process includes
estimating a transmission time difference between a first signal
and a second signal exchanged between the wireless device 20 and a
first network node 34 and a second network node 34, respectively
(block S260). The process also includes obtaining a threshold based
on the first numerology and the second numerology (block S270). The
process further includes determining the synchronization status of
the wireless device 20 based on a comparison between the estimated
transmission time difference and the threshold (block S280).
[0184] FIG. 13 is a flowchart of an exemplary process performed by
a network node 34 for determining a synchronization status for a
wireless device. The process includes obtaining, from the wireless
device 20, an estimated transmission time difference between a
first signal and a second signal exchanged between the wireless
device 20 and a first network node 34 and a second network node 34
respectively (block S290). The process also includes obtaining a
threshold based on the first numerology and the second numerology
(block S300). The process further includes determining the
synchronization status of the wireless device 20 based on a
comparison between the estimated transmission time difference and
the threshold (block S320).
[0185] In some embodiments, the first signal is a first downlink
signal from the first network node and the second signal is a
second downlink signal from the second network node and estimating
the transmission time difference comprises estimating a time
difference between receipt of the first downlink signal received
from the first network node and receipt of the second downlink
signal received from the second network node.
[0186] In some embodiments, obtaining the threshold comprises
obtaining a downlink threshold. In this case, determining the
synchronization status comprises determining the synchronization
status based on a comparison between the estimated time difference
and the downlink threshold. The first signal may be a first uplink
signal and the second signal is a second uplink signal and
estimating the transmission time difference comprises estimating a
time difference between transmitting the first uplink signal to the
first network node and transmitting the second uplink signal to the
second network node. Obtaining the threshold may include obtaining
an uplink threshold. In this case, determining the synchronization
status comprises determining the synchronization status based on a
comparison between the estimated time difference and the uplink
threshold. The first numerology may be used for operating the first
downlink signal and the second numerology is used for operating a
second downlink signal. The first network node 34 and the second
network node 34 may be the same node. Alternatively, the first
network node 34 and the second network node 34 may be different
nodes. The method may further include indicating to another node,
information about capability of the wireless device 20 related to
support of at least one of synchronous and asynchronous
multi-connectivity. The indication may be sent to the other node in
response to receipt of a request from the other node. The method
may further include using the determined synchronization status of
the wireless device 20 for at least one operational task. The at
least one operational task may comprise at least one of
demodulation of received signals, transmission of signals, radio
measurements, at least one of selection and application of a power
control scheme, transmission of at least one of the estimated time
difference and an uplink transmit time difference to another
wireless device, transmission of at least one of the estimated time
difference and the uplink transmit time difference to another
network node 34, and indicating the synchronization status of the
wireless device 20 to at least one of another network node 34 or
another wireless device 20. The downlink threshold may be selected
from a table of thresholds corresponding to different subcarrier
spacings. In some embodiments, the synchronization status of the
wireless device 20 is synchronized when the estimated time
difference exceeds the downlink threshold and is asynchronous
otherwise. The process may comprise obtaining a second downlink
threshold based on the first numerology and the second numerology
and determining the synchronization status of the wireless device
is based on a comparison between the estimated time difference and
the second downlink threshold. The magnitude of the first downlink
threshold may decrease with the increase in the subcarrier spacing
used in at least one of the first downlink cell and the second
downlink cell. The process may comprise obtaining a second uplink
threshold based on the first numerology and the second numerology
and determining the synchronization status of the wireless device
is based on a comparison between the estimated time difference and
the second uplink threshold. The magnitude of the second downlink
threshold may decrease with the increase in the subcarrier spacing
used in at least one of the first downlink cell and the second
downlink cell.
[0187] According to another aspect, some embodiments include a
wireless device 20 configured to determine a synchronization status
for the wireless device 20 based on a first numerology and a second
numerology. The wireless device 20 includes a communications
interface 32. The wireless device also includes processing
circuitry 22 configured to perform the process/method of FIG.
12.
[0188] In some embodiments, a method performed by a network node 34
for determining a synchronization status for a wireless device 20
based on a first numerology and a second numerology defined for
data transmission is provided. The method comprises: obtaining,
from the wireless device, an estimated transmission time difference
between a first signal and a second signal exchanged between the
wireless device and a first network node and a second network node
respectively (block S290); obtaining a threshold based on the first
numerology and the second numerology (block S300); and determining
the synchronization status of the wireless device based on a
comparison between the estimated transmission time difference and
the threshold (block S320) . . . . The first signal may be a first
downlink signal from the first network node and the second signal
is a second downlink signal from the second network node and
estimating the transmission time difference comprises estimating a
time difference between receipt of the first downlink signal
received from the first network node and receipt of the second
downlink signal received from the second network node. Obtaining
the threshold may comprise obtaining a downlink threshold. In this
case, the comparison is between the estimated transmission time
difference and the downlink threshold. In some embodiments, the
first signal is a first uplink signal and the second signal is a
second uplink signal and wherein estimating the transmission time
difference comprises estimating a time difference between
transmitting the first uplink signal to the first network node and
transmitting the second uplink signal to the second network node.
Obtaining the threshold may comprise obtaining an uplink threshold.
In this case, the comparison is between the estimated transmission
time difference and the uplink threshold. The process may comprise
obtaining a second uplink threshold based on the first numerology
and the second numerology and determining the synchronization
status of the wireless device is based on a comparison between the
estimated transmission time difference and the second uplink
threshold, A magnitude of the second uplink threshold may decrease
with an increase in subcarrier spacing used in at least one of a
first uplink cell and a second uplink cell.
[0189] In some embodiments, the first numerology is used for
operating the first downlink signal and the second numerology is
used for operating the second downlink signal. The first network
node 34 and the second network node 34 may be the same node.
Alternatively, the first network node 34 and the second network
node 34 may be different nodes. In some embodiments, the method
further includes obtaining information about capability of the
wireless device 20 related to support of at least one of
synchronous and asynchronous multi-connectivity. The information
may be received from the wireless device 20 in response to a
request for the information from the network node 34. The method
may further include using the determined synchronization status of
the wireless device 20 for at least one operational task. The at
least one operational task may include at least one of reception of
signal from the wireless device 20, transmission of signals to the
wireless device 20, scheduling of at least one of uplink and
downlink signals, radio measurements, timing advance estimation,
adaptation of configuration of measurement gaps, adaptation of the
discontinuous reception, DRX, configuration used for the wireless
device, adaptation of measurement configuration sent to the
wireless device, configuration of a timing advance group, at least
one of selection and configuration of a power control scheme, and
transmission of at least one of the estimated time difference and
an uplink transmit time difference to another network node 34, A
magnitude of the uplink threshold may decrease with an increase in
subcarrier spacing used in at least one of a first uplink cell and
a second uplink cell. In some embodiments, a network node 34 is
configured to perform all the steps of the method of FIG. 13. More
specifically, the network node 34 comprises a processing circuitry
configured to perform the embodiments and functionalities provided
by the methods described herein.
[0190] Some embodiments include:
Embodiment 1
[0191] A method performed by a wireless device for determining a
synchronization status for the wireless device based on a first
numerology and a second numerology, the method comprising:
[0192] estimating a time difference between receipt of a first
downlink signal received from a first network node, and receipt of
a second downlink signal received from a second network node;
[0193] obtaining a first downlink threshold based on the first
numerology and the second numerology; and
[0194] determining the synchronization status of the wireless
device based on a relationship between the estimated time
difference and the first downlink threshold.
Embodiment 2
[0195] The method of Embodiment 1, wherein the first numerology is
used for operating the first downlink signal and the second
numerology is used for operating the second downlink signal.
Embodiment 3
[0196] The method of Embodiment 1, wherein the first network node
and the second network node are a same node.
Embodiment 4
[0197] The method of Embodiment 1, wherein the first network node
and the second network node are different nodes.
Embodiment 5
[0198] The method of Embodiment 1, further comprising indicating to
another node, information about capability of the wireless device
related to support of at least one of synchronous and asynchronous
multi-connectivity.
Embodiment 6
[0199] The method of Embodiment 5, wherein the indication is sent
to the other node in response to receipt of a request from the
other node.
Embodiment 7
[0200] The method of Embodiment 1, further comprising using the
determined synchronization status of the wireless device for at
least one operational task.
Embodiment 8
[0201] The method of Embodiment 7, wherein the at least one
operational task comprises at least one of demodulation of received
signals, transmission of signals, radio measurements, at least one
of selection and application of a power control scheme,
transmission of at least one of the estimated time difference and
an uplink transmit time difference to another wireless device,
transmission of at least one of the estimated time difference and
the uplink transmit time difference to another network node, and
indicating the synchronization status of the wireless device to at
least one of another network node or another wireless device.
Embodiment 9
[0202] The method of Embodiment 1, further comprising estimating,
at the wireless device, a transmit time difference between a first
uplink signal transmitted by the wireless device in a first cell
operated by the first network node a second uplink signal
transmitted by the wireless device in a second cell operated by the
second network node.
Embodiment 10
[0203] A wireless device configured to determine a synchronization
status for the wireless device based on a first numerology and a
second numerology, the wireless device comprising:
[0204] a communications interface; and
[0205] processing circuitry including a memory and one or more
processors, the memory in communication with the one or more
processors, the memory configured to store first signal sequences
and second signal sequences, the memory having instructions that,
when executed by the one or more processors, configure the one or
more processors to: [0206] estimate a time difference between
receipt of a first downlink signal received from a first network
node, and receipt of a second downlink signal received from a
second network node; [0207] obtain a first downlink threshold based
on the first numerology and the second numerology; and [0208]
determine the synchronization status of the wireless device based
on a relationship between the estimated time difference and the
first downlink threshold.
Embodiment 11
[0209] The wireless device of Embodiment 10, wherein the first
numerology is used for operating the first downlink signal and the
second numerology is used for operating the second downlink
signal.
Embodiment 12
[0210] The wireless device of Embodiment 10, wherein the first
network node and the second network node are a same node.
Embodiment 13
[0211] The wireless device of Embodiment 10, wherein the first
network node and the second network node are different nodes.
Embodiment 14
[0212] The wireless device of Embodiment 10, wherein the
communications interface is configured to indicate to another node,
information about capability of the wireless device related to
support of at least one of synchronous and asynchronous
multi-connectivity.
Embodiment 15
[0213] The wireless device of Embodiment 14, wherein the indication
is sent to the other node in response to receipt of a request from
the other node.
Embodiment 16
[0214] The wireless device of Embodiment 10, wherein the one or
more processors is further configured to use the determined
synchronization status of the wireless device for at least one
operational task.
Embodiment 17
[0215] The wireless device of Embodiment 16, wherein the at least
one operational task comprises at least one of demodulation of
received signals, transmission of signals, radio measurements, at
least one of selection and application of a power control scheme,
transmission of at least one of the estimated time difference and
an uplink transmit time difference to another wireless device,
transmission of at least one of the estimated time difference and
the uplink transmit time difference to another network node, and
indicating the synchronization status of the wireless device to at
least one of another network node or another wireless device.
Embodiment 18
[0216] The wireless device of Embodiment 10, wherein the one or
more processors is further configured to estimate a transmit time
difference between a first uplink signal transmitted by the
wireless device in a first cell operated by the first network node
a second uplink signal transmitted by the wireless device in a
second cell operated by the second network node.
Embodiment 19
[0217] A method performed by a network node for determining a
synchronization status for a wireless device based on a first
numerology and a second numerology, the method comprising:
[0218] obtaining, from the wireless device, an estimated time
difference between receipt, by the wireless device of a first
downlink signal received from a first network node, and receipt, by
the wireless device of a second downlink signal received from a
second network node;
[0219] obtaining a first downlink threshold based on the first
numerology and the second numerology; and
[0220] determining the synchronization status of the wireless
device based on a relationship between the estimated time
difference and the first downlink threshold.
Embodiment 20
[0221] The method of Embodiment 19, wherein the first numerology is
used for operating the first downlink signal and the second
numerology is used for operating the second downlink signal.
Embodiment 21
[0222] The method of Embodiment 19, wherein the first network node
and the second network node are a same node.
Embodiment 22
[0223] The method of Embodiment 19, wherein the first network node
and the second network node are different nodes.
Embodiment 23
[0224] The method of Embodiment 19, further comprising obtaining
information about capability of the wireless device related to
support of at least one of synchronous and asynchronous
multi-connectivity.
Embodiment 24
[0225] The method of Embodiment 23, wherein the information is
received from the wireless device in response to a request for the
information from the network node.
Embodiment 25
[0226] The method of Embodiment 19, further comprising using the
determined synchronization status of the wireless device for at
least one operational task.
Embodiment 26
[0227] The method of Embodiment 25, wherein the at least one
operational task comprises at least one of reception of signal from
the wireless device, transmission of signals to the wireless
device, scheduling of at least one of uplink and downlink signals,
radio measurements, timing advance estimation, adaptation of
configuration of measurement gaps, adaptation of the discontinuous
reception, DRX, configuration used for the wireless device,
adaptation of measurement configuration sent to the wireless
device, configuration of a timing advance group, at least one of
selection and configuration of a power control scheme, and
transmission of at least one of the estimated time difference and
an uplink transmit time difference to another network node.
Embodiment 27
[0228] The method of Embodiment 19, further comprising obtaining,
at the network node, a transmit time difference, estimated by the
wireless device, between a first uplink signal transmitted by the
wireless device in a first cell a second uplink signal transmitted
by the wireless device in a second cell.
Embodiment 28
[0229] A network node configured to determine a synchronization
status for a wireless device based on a first numerology and a
second numerology, the network node comprising:
[0230] a communications interface configured to: [0231] obtain,
from the wireless device, an estimated time difference between
receipt, by the wireless device of a first downlink signal received
from a first network node, and receipt, by the wireless device of a
second downlink signal received from a second network node; [0232]
obtain a first downlink threshold based on the first numerology and
the second numerology; and
[0233] processing circuitry including a memory and one or more
processors, the memory in communication with the one or more
processors, the memory configured to store first signal sequences
and second signal sequences, the memory having instructions that,
when executed by the one or more processors, configure the one or
more processors to: [0234] determine the synchronization status of
the wireless device based on a relationship between the estimated
time difference and the first downlink threshold.
Embodiment 29
[0235] The network node of Embodiment 28, wherein the first
numerology is used for operating the first downlink signal and the
second numerology is used for operating the second downlink
signal.
Embodiment 30
[0236] The network node of Embodiment 28, wherein the first network
node and the second network node are the same.
Embodiment 31
[0237] The network node of Embodiment 28, wherein the first network
node and the second network node are different.
Embodiment 32
[0238] The network node of Embodiment 28, wherein the
communications interface is further configured to obtain
information about capability of the wireless device related to
support of at least one of synchronous and asynchronous
multi-connectivity.
Embodiment 33
[0239] The network node of Embodiment 32, wherein the information
is received from the wireless device in response to a request for
the information from the network node.
Embodiment 34
[0240] The network node of Embodiment 28, wherein the one or more
processors is further configured to use the determined
synchronization status of the wireless device for at least one
operational task.
Embodiment 35
[0241] The network node of Embodiment 34, wherein the at least one
operational task comprises at least one of reception of signal from
the wireless device, transmission of signals to the wireless
device, scheduling of at least one of uplink and downlink signals,
radio measurements, timing advance estimation, adaptation of
configuration of measurement gaps, adaptation of the discontinuous
reception, DRX, configuration used for the wireless device,
adaptation of measurement configuration sent to the wireless
device, configuration of a timing advance group, at least one of
selection and configuration of a power control scheme, and
transmission of at least one of the estimated time difference and
an uplink transmit time difference to another network node.
Embodiment 36
[0242] The network node of Embodiment 28, wherein the
communications interface is further configured to obtain a transmit
time difference, estimated by the wireless device, between a first
uplink signal transmitted by the wireless device in a first cell a
second uplink signal transmitted by the wireless device in a second
cell.
Embodiment 37
[0243] A wireless device configured to determine a synchronization
status for the wireless device based on a first numerology and a
second numerology, the wireless device comprising:
[0244] a memory module;
[0245] a time difference estimation module configured to estimate a
time difference between receipt of a first downlink signal received
from a first network node, and receipt of a second downlink signal
received from a second network node; and
[0246] a synchronization status determination module configured to:
[0247] obtain a first downlink threshold based on the first
numerology and the second numerology; and [0248] determine the
synchronization status of the wireless device based on a
relationship between the estimated time difference and the first
downlink threshold.
Embodiment 38
[0249] A network node configured to determine a synchronization
status for a wireless device based on a first numerology and a
second numerology, the network node comprising:
[0250] a communications interface module configured to: [0251]
obtain, from the wireless device, an estimated time difference
between receipt, by the wireless device of a first downlink signal
received from a first network node, and receipt, by the wireless
device of a second downlink signal received from a second network
node; and [0252] obtain a first downlink threshold based on the
first numerology and the second numerology; and
[0253] a synchronization status determination module configured to
determine the synchronization status of the wireless device based
on a relationship between the estimated time difference and the
first downlink threshold.
[0254] As will be appreciated by one of skill in the art, the
concepts described herein may be embodied as a method, data
processing system, and/or computer program product. Accordingly,
the concepts described herein may take the form of an entirely
hardware embodiment, an entirely software embodiment or an
embodiment combining software and hardware aspects all generally
referred to herein as a "circuit" or "module." Furthermore, the
disclosure may take the form of a computer program product on a
tangible computer usable storage medium having computer program
code embodied in the medium that can be executed by a computer. Any
suitable tangible computer readable medium may be utilized
including hard disks, CD-ROMs, electronic storage devices, optical
storage devices, or magnetic storage devices.
[0255] Some embodiments are described herein with reference to
flowchart illustrations and/or block diagrams of methods, systems
and computer program products. It will be understood that each
block of the flowchart illustrations and/or block diagrams, and
combinations of blocks in the flowchart illustrations and/or block
diagrams, can be implemented by computer program instructions.
These computer program instructions may be provided to one or more
processors of a general purpose computer (to thereby create a
special purpose computer), special purpose computer, or other
programmable data processing apparatus to produce a machine, such
that the instructions, which execute via the one or more processors
of the computer or other programmable data processing apparatus,
create means for implementing the functions/acts specified in the
flowchart and/or block diagram block or blocks.
[0256] These computer program instructions may also be stored in a
computer readable memory or storage medium that can direct a
computer or other programmable data processing apparatus to
function in a particular manner, such that the instructions stored
in the computer readable memory produce an article of manufacture
including instruction means which implement the function/act
specified in the flowchart and/or block diagram block or
blocks.
[0257] The computer program instructions may also be loaded onto a
computer or other programmable data processing apparatus to cause a
series of operational steps to be performed on the computer or
other programmable apparatus to produce a computer implemented
process such that the instructions which execute on the computer or
other programmable apparatus provide steps for implementing the
functions/acts specified in the flowchart and/or block diagram
block or blocks.
[0258] It is to be understood that the functions/acts noted in the
blocks may occur out of the order noted in the operational
illustrations. For example, two blocks shown in succession may in
fact be executed substantially concurrently or the blocks may
sometimes be executed in the reverse order, depending upon the
functionality/acts involved. Although some of the diagrams include
arrows on communication paths to show a primary direction of
communication, it is to be understood that communication may occur
in the opposite direction to the depicted arrows.
[0259] Computer program code for carrying out operations of the
concepts described herein may be written in an object oriented
programming language such as Java.RTM. or C++. However, the
computer program code for carrying out operations of the disclosure
may also be written in conventional procedural programming
languages, such as the "C" programming language. The program code
may execute entirely on the user's computer, partly on the user's
computer, as a stand-alone software package, partly on the user's
computer and partly on a remote computer or entirely on the remote
computer. In the latter scenario, the remote computer may be
connected to the user's computer through a local area network (LAN)
or a wide area network (WAN), or the connection may be made to an
external computer (for example, through the Internet using an
Internet Service Provider).
[0260] Many different embodiments have been disclosed herein, in
connection with the above description and the drawings. It will be
understood that it would be unduly repetitious and obfuscating to
literally describe and illustrate every combination and
subcombination of these embodiments. Accordingly, all embodiments
can be combined in any way and/or combination, and the present
specification, including the drawings, shall be construed to
constitute a complete written description of all combinations and
subcombinations of the embodiments described herein, and of the
manner and process of making and using them, and shall support
claims to any such combination or subcombination.
[0261] It will be appreciated by persons skilled in the art that
the embodiments described herein are not limited to what has been
particularly shown and described herein above. In addition, unless
mention was made above to the contrary, it should be noted that all
of the accompanying drawings are not to scale. A variety of
modifications and variations are possible in light of the above
teachings, which are limited only by the scope of the claims.
* * * * *